Dinosaur Soft Tissue Found in the Strangest Place

Discovery could change how we study dino physiology and how we analyze fossils.

Among the fossils studied was this claw of an unidentified theropod, found in Canada in the early 20th century. I

Laurent Mekul

An off-the-clock project
begun on a whim may cause
paleontologists and museum
curators to rethink their fossil
collections.

Preserved soft tissue from
dinosaurs is limited to a handful
of exceptional specimens. In all but
the most unusual circumstances,
the tissue breaks down quickly
after death — even remnant
proteins were believed to last a few
million years at most.

In June, however, researchers
reported evidence of blood cells
and collagen fibers in poor-quality
fossil fragments that were 75 million
years old. The discovery opens a
new avenue into studying dinosaur
physiology and could spur changes
in how fossils are analyzed.

After analyzing the claw, researchers found structures resembling blood cells, shown in red.

Sergio Bertazzo/Imperial College London

The project was born when paleontologist Susannah Maidment and biomedical researcher Sergio Bertazzo struck up a casual conversation at Britain’s Imperial College London. Bertazzo, who researches microcalcification in living tissue, was curious to see what fossils looked like under a scanning electron microscope. Maidment, who studies dinosaur motion, was intrigued, too.

“The museum was worried we would destroy whatever they gave us, so they gave us ‘bad’ samples that were just sitting there for more than 100 years,” says Bertazzo.

Bertazzo was shocked when he saw what appeared to be blood cells in the fossils. Maidment was skeptical: “I thought it had to be bacteria, or pollen, or modern contamination.”

But additional research has confirmed that structures resembling blood cells and collagen protein fibers — key elements of connective tissue — were preserved in six of eight fragments. The findings mean that even subpar fossils discarded at digs or tossed in museum collection junk drawers could yield valuable evidence about how dinosaurs lived and evolved.